The main function of a spring contact finger is to:

1. Ensure that the battery is not accidentally removed to prevent the spring from rebounding and injuring the person who accidentally touches it.

2. It plays a certain limiting role to prevent the sensor from detecting objects and causing a short circuit in the sensor.

In addition, the spring finger also has the following small knowledge:

1. Spring contact refers to a small component on electronic devices, usually used to connect metal sheets on the device, playing a role in connection and fixation.

2. The material of the spring contact finger is generally stainless steel, because stainless steel has good corrosion resistance, is not easy to age, and has a beautiful appearance.

3. The spring contact finger can be processed into various shapes according to usage needs, such as circular, square, trapezoidal, etc.

4. It can be understood as a lever principle, with one end fixed and the other end movable. When the force reaches a certain limit, it will trigger this movable end and bounce up.